Treatment of latex



Patented Oct. 4, 1932 ZHN D. S ATE PATENT OLFFICE) ALEXANDER A. NIKITIN, OF PASSAIC, NEW JERSEY, ASSIGNOR TO THE NAUGATUGK CHEMICAL COMPANY, OF NAUGATUOK, CONNECTICUT, A CORPORATION OF GON- NEGTIOUT ,N o Drawing.

such as Irish moss, Karaya gum, tragacanth gum, pectin, pectin-allied bodies, ammonium alginate etc. The degree of creaming, concentration'of solids, viscosity etc. depends a good deal on the natureand amount of creaming agent used, but even with all precautions, the final result'will not correspond 1o to'that desired. Itseems that-the creaming action continues even after a period of standingto allow separation. This disadyantage canbe best illustrated with ammonium alginate as a the icreaming agent. :5 Ammonium ,alginate is very useful in obtaining a high concentration of total solids in the cream, but if the creainso prepared 7 is allowed to stand, or diluted, as is sometimes the case forthe proper preparation of io 'a latex compound,creaming continues. For instance in the preparation of quick depositing gloves on porous forms from such 1 a creamed latex the creamed latex in con- 1 tinuing to cream, forms a very concentrated layer at the surface which produces thin coagulum, and consequently less concentrat-- ed layer at the bottom of the vessel-with the result of a non-uniform dipped product. I

Y Ithas been found that certain substances will avoidthis'troublesome feature and they are designatedfnegative or anti-creaming agents. Saponin is the bestv illustration of this class'. i

. Accordingly the invention comprises addingthe' anti-creaming agent to the latexsub Application filed April 16,

TREATMENT OF LATEX 1929. Serial No. 355,676.

sequent to creaming. Further creaming is thereby avoided. By this means it is possible to cream a latex to any desired concentration without difliculty. In other words concentration of 40, 45, 50, 55, 60 percent of total solids in the cream can be attained at will. No stirring, shaking or agitation of the vessel containing the latex, thus causing introduction of air bubbles, will be necessary. 7

Example 1.' To 1000 grams of ammonia preserved latex, isv added .72 gram ammonium alginate; when a cream of a solids concentration of 50% is reached, there is added to the cream about 1 part of saponin per 100 parts of solids in the cream, after the serum is removed. Further creaming is retarded.

Although the amount of anti-creaming agent maybe reasonably varied, in general the best results are obtained with substan- 4' tially 3 parts per 100 parts of solids, of the negative creaming agent.

With the detailed disclosure above given 0 it is obvious that modifications will suggest themselves and it is not desired to limit the invention otherwise than as set forth in the appended claims. I

Having thus described my invention, what I claim and desire to protect by Letters Pat- I ent is:

1. A method of controlling the crcaming of latex which comprises treating latex with ammonium alginate, allowlng' the mixture to cream, removing the watery serum portion,

and adding an anti-creaming agent to the creamed latex.

2. The method of controllng the creaming of latex which-comprises treating latex with ammonium alginate, allowing the mixture to cream, removing the watery serum portion,

and adding s'aponin to the creamed latex.

3. A method of controlling the creaming of latex which comprises treating latex with ammonium alginate, allowing the mixture to cream, removing the watery serum portion,

and adding to the creamed latex substantially 7, and adding to the creamed latex about 1 part I of saponin; per 100 parts of solids.

I ISignedat'Passaie, county of Passaic, State of New Jersey,1this 12 day of April, 1929.

I v ALEXANDER IA; I ITI 

